| 摘要 |
PURPOSE:To largely improve the withstand voltage of a P-N junction by a method wherein the formation of a different conductive region in a conductive region is performed by thinning a mask window from the periphery toward the aperture edge, and it is formed by increasing the curvature radius of the bottom corner to the direction of the depth. CONSTITUTION:The surface of the N type conductive region 1 of a wafer is masked with an oxide film of Si oxide having the window 4. The mask window 4 is formed thin from the periphery toward the aperture edge 5. The wafer is placed in the atmosphere of impurity gas such as boron, and the impurity gas is diffused into the N type conductive region 1 by heat-diffusion. Thus, the formation of the P type conductive region 2 of a large curvature radius of the corner 3 to the direction of the depth resultes, and then the pair voltages generated by the P-N junction increase. |
